VL53L5CX platform code using Raspberry Pi Pico

[vinc00]

Hi there,

I'm currently trying to write the platform code for the VL53L5CX using a Raspberry Pi Pico.

I'm trying to publish the sensor data via micro-ROS in a ROS2 topic. When I use my current code I only get values close to zero and they are the same every time so I think the problem is in the I2C connection. I used an I2C-Scan so I know that the address is 0x29.

The only thing I could find online that was close to a platform code using a Pico was the platform code for a VL53L1X. Could anybody tell what I did wrong or how I have to configure the platform code for the VL53L1X so I can use it with the VL53L5CX.

Thanks a lot :)

Current platform.c:

/**
  *
  * Copyright (c) 2021 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

#include "hardware/i2c.h"
#include <stdbool.h>
#include "platform.h"

uint8_t VL53L5CX_WrByte(
    VL53L5CX_Platform *p_platform,
    uint16_t RegisterAdress,
    uint8_t value)
{
    uint8_t buffer[3];
    buffer[0] = (RegisterAdress >> ‌8)‌ & 0xFF;
    buffer[1] = RegisterAdress & 0xFF;
    buffer[2] = value;

    p_platform->address = 0x29;

    int result = i2c_write_blocking(i2c0, p_platform->address, buffer, sizeof(buffer), false);
    return (result < 0) ? 1 : 0;
}


uint8_t VL53L5CX_RdByte(
    VL53L5CX_Platform *p_platform,
    uint16_t RegisterAdress,
    uint8_t *p_value)
{
    uint8_t buffer[2];
    buffer[0] = (RegisterAdress >> ‌8)‌ & 0xFF;  // High-Byte der Registeradresse
    buffer[1] = RegisterAdress & 0xFF;         // Low-Byte der Registeradresse

    p_platform->address = 0x29;

    // Registeradresse senden
    int result = i2c_write_blocking(i2c0, p_platform->address, buffer, sizeof(buffer), true);
    if (result < 0)
    {
        return 1;  // Fehler
    }

    // Byte lesen
    result = i2c_read_blocking(i2c0, p_platform->address, p_value, 1, false);
    return (result < 0) ? 1 : 0;  // 0 = Erfolg, 1 = Fehler
}


uint8_t VL53L5CX_WrMulti(
    VL53L5CX_Platform *p_platform,
    uint16_t RegisterAdress,
    uint8_t *p_values,
    uint32_t size)
{
    p_platform->address = 0x29;

    uint8_t buffer[2 + size];
    buffer[0] = (RegisterAdress >> ‌8)‌ & 0xFF;  // High-Byte der Registeradresse
    buffer[1] = RegisterAdress & 0xFF;         // Low-Byte der Registeradresse
    memcpy(&buffer[2], p_values, size);        // Daten kopieren

    int result = i2c_write_blocking(i2c0, p_platform->address, buffer, sizeof(buffer), false);
    return (result < 0) ? 1 : 0;  // 0 = Erfolg, 1 = Fehler
}


uint8_t VL53L5CX_RdMulti(
    VL53L5CX_Platform *p_platform,
    uint16_t RegisterAdress,
    uint8_t *p_values,
    uint32_t size)
{
    p_platform->address = 0x29;

    uint8_t buffer[2];
    buffer[0] = (RegisterAdress >> ‌8)‌ & 0xFF;  // High-Byte der Registeradresse
    buffer[1] = RegisterAdress & 0xFF;         // Low-Byte der Registeradresse

    // Registeradresse senden
    int result = i2c_write_blocking(i2c0, p_platform->address, buffer, sizeof(buffer), true);
    if (result < 0)
    {
        return 1;  // Fehler
    }

    // Daten lesen
    result = i2c_read_blocking(i2c0, p_platform->address, p_values, size, false);
    return (result < 0) ? 1 : 0;  // 0 = Erfolg, 1 = Fehler
}

uint8_t VL53L5CX_Reset_Sensor(
		VL53L5CX_Platform *p_platform)
{
	uint8_t status = 0;
	
	/* (Optional) Need to be implemented by customer. This function returns 0 if OK */
	
	/* Set pin LPN to LOW */
	/* Set pin AVDD to LOW */
	/* Set pin VDDIO  to LOW */
	VL53L5CX_WaitMs(p_platform, 100);

	/* Set pin LPN of to HIGH */
	/* Set pin AVDD of to HIGH */
	/* Set pin VDDIO of  to HIGH */
	VL53L5CX_WaitMs(p_platform, 100);

	return status;
}

void VL53L5CX_SwapBuffer(
		uint8_t 		*buffer,
		uint16_t 	 	 size)
{
	uint32_t i, tmp;
	
	/* Example of possible implementation using <string.h> */
	for(i = 0; i < size; i = i + 4) 
	{
		tmp = (
		  buffer[i]<<24)
		|(buffer[i+1]<<16)
		|(buffer[i+2]<<8)
		|(buffer[i+3]);
		
		memcpy(&(buffer[i]), &tmp, 4);
	}
}	

uint8_t VL53L5CX_WaitMs(
		VL53L5CX_Platform *p_platform,
		uint32_t TimeMs)
{
	uint8_t status = 255;

	/* Need to be implemented by customer. This function returns 0 if OK */
	
	return status;
}

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[John E KVAM]

A couple of comments:

Check Gethub. The linux community is good at sharing code. I found GitHub - akionu/pico-vl53l5cx: A Tiny Library for ST's VL53L5CX using Raspberry Pi Pico C/C++ SDK 

which looks very promising. 

 In my experience the i2c issues generally boil down to byte-swap (and word-swap) issues. 

Sometimes I see a set-up with long wires, and that can cause electrical issues. But if you aren't getting anywhere at the start, it's a byte-swap issue.

Checkout the github, and see what they did. That should get you going. 

- john